Mounting for switches and other electrical apparatus



Oct. 31, 1933. T. E. MURRAY ET AL 13,935

IOUfiTING FOR SWITCHES AND OTHER ELECTRICAL APPARATUS Original Filed Sept. 21. 1920 2 Sheets-Sheet l '4? wvui'? 3% 0 Tg n 2/ 6' m I v fiu/eIz/ars 7 120% Z: M J?! M [Zoms flm vgg we! Jylkhymkhzz lkwz'oe ar 0.

Oct. 31, 1933. T. E. MURRAY ETAL Re. 18,985

HOUNTING FOR SWITCHES AND OTHER ELECTRICAL APPARATUS Original Filed Sept. 21. 1920 2 Sheets-Sheet 2 Z? ,Zra/en/ansmzzuzalf filaz m J rezzd flmmzzo' 1i. Marla-55 mead f y fleaa'ce (Z271- Jsp'ynee Reissuecl Oct. 31, 1933 MOUNTING FOR SWITCHES AND OTH R 1 ELECTRICAL APPARATUS' Thomas E. Murray,

deceased, late of Brooklyn,

by Metropolitan Device Corporation, Brooklyn, assignee, and Thomas E. Murray, Jr., Brooklyn, N. Y.

Original No. 1,726,914, dated September Serial No. 411,824, September 21, 1920.

3, 1929, Application for reissue' September 3, 1931. Serial No.

provements especially in the direction of economy, accuracyand reliability in this class of devices. '5 The accompanying drawings illustrate embodiments of our invention.

Fig. l is a plan of a two-bladed switch with fuse connections all enclosed in a'box;

Fig. 2 is a longitudinal section of the box, the

usual cover being omitted, the electrical devices being in elevation;

Figs. 3 and 4 are transverse sections of the electrical apparatus on the lines 3-3 and 44 of Fig. 2;

Fig. 5 is a section similar to Fig. 2 illustrating a modified construction.

In electrical apparatus of this class and particularly electric switches carried in metalboxes it is customary to mount the several electrically 0 separate parts of the apparatus on a common block of porcelain or similar insulating material which is mounted within the steel box. Such porcelain blocks are comparatively expensive and subject to comparatively easy breakage. It

' 5 is difficult also to mold such blocks with accuracy.

We purpose to avoid these disadvantages by using a metal holder, which is directly a part of the box itself, and to fasten the electrically sepa- 3 rated parts of the apparatus to such holder and to insulate them separately therefrom. Such boxes may be made cheaply and accurately of drawn or pressed steel or other metal which is not liable to break in transportation or use.

Referring first to Figs. 1 to 4, there are two posts 1 each carrying a pivoted end of one of the blades 2 which are operated by an insulated cross-bar 3 and arm 4. Opposite the posts 1 are posts 5 each composed of two. leaves between which the free ends of the blades fit when the switch is closed, and from which the blades are withdrawn when the switch is open. For receiving the usual fuses there are two sockets 6 each mounted on a small plate or flange 7 and in each socket there is a contact tongue 8, the outer end of which constitutes a plate or flange 9, the plates 7 and 8 serving to fasten these parts to their support. The tongues 8 are insulated from the sockets by means of mica plates 10 Fig. 4)

Each of the parts 1, 5, 7 and 9 above described is provided with a binding screw 11 for attachment of a wire; the wires passing out through the walls of the box in any usual or suitable way,

not illustrated.

.5 Claims. (o1. 247-4))v Our invention aims to providecertain im-q The several fixed parts described are mounted on a-holder comprising a plate 12 which is a raised portion of the box or enclosure in which the electrical devices arecarried. This plate is formed with hollow upward projections 13, one corresponding to each of the posts or fixed "sup porting parts of the'electrical apparatus, and each of "such parts is fastened separately on the corresponding projection 13. A screw 14 passes through an enlarged opening in the end of the projection, its head 15 going easily within the -hollow thereof, and engages the supporting post or plate or" the electrical apparatus, as 5 or 9 in Figs. 3 and 4. The central part of the screw is surrounded by an insulating bushing 16, and a' 70. washer 17 of mica or other insulating material further separates the screw head from the steel holder. A washer 18 is interposed between the fixed ,part of the electrical apparatus and the metal holder, and is preferably made large enough to extend beyond the sides of the projection 13 so as to ensure against accidental connection between the electrical apparatus and the projection on the metal holder. For further holding the screw and insulating its head the projection 13 is filled with a body 19 of plastic insulating mate rial so as -to embed the parts of the screw therein.

According to Fig. 2 the plate or holder 12 is elevatedabove the bottom and is bent at its ends to form spacing portions 20 which are bent up from the bottom 22 of the steel box, the sides of which are indicated at 23.

By this construction the separate parts of the electrical apparatus are firmly and accurately mounted in exact relation with each other and are abundantly protected from short circuiting bymoisture or other accidental connection, and the construction is considerably cheaper as well as better than that heretofore employed for similar apparatus. i

Fig. 5 illustrates several modifications in detail. The bottom of the box is bent up to form a plate 26 to which the posts of the apparatus are fas-' tened. The screws 14 are arranged to clamp the two mica washers 27 and 28 together, or nearly 100 so, the opening through the holder being made sufiiciently large to permit this and the bottom of the posts being convexed slightly to assist in securing this result. This detail of insulation may be applied equally to the construction of I the fastenings are applied, by abody 29 of insulating cement. The holder or the box maybe enameled or otherwise treated to prevent rusting,

=1arity of'detail certain embodiments of our in-' vention, yet it is not to be understood therefrom or it may be without such enameling. The fastening screws referred to may equally wellf be rivets and may be square or round or of other suitable cross-section, and the holes through which they pass may also be ofvarious'shapes.

The bottom of the box in Fig.2 may be open below the holder 12 as shown to save metal and to give access to the underside of the holder, or

it may be closed solidly. And in either case the space within the holder may be filledwith insu-' lating cement. V 7

Though we have described with great particuthat the invention is restricted to the particular embodiments illustrated. Various modifications thereof in detail and in the arrangement of the parts may be madeby those skilled in the art without departure from-our inventionas defined in the following claims. I

Whatwe' claim is 1. The combination with an electric cut-out'of a metal enclosure therefor having a raised por-' tion of a wall thereof constituting a base on which the opposite terminalmembers of the cut-out are mounted with insulating washers for separating 'said terminals from the base' and from each other.

I .2.'The combination with an electriccut-out of a metalenclosure therefor having a raised portion of a wall thereof constituting a base on which the opposite terminal members of the cut-out are 1 mounted with separate-insulating washers for each of said terminals for separating it from the other terminal and from the base.

. 3. The combination with an electric cut-out of ametalenclosure therefor having a raised portion of a wall thereof constituting a base on which the opposite terminalmembers of the cut-out are mounted andinsulating material separating said terminals from the base and from each other. 7

4. The apparatus of claim 3 in which said insulating materialis in layers one on each face of said raised portion beneath said terminals.

5. The apparatus of claim 3 in which said raised portion is continuous and integral with thewrall of said box.

METROPOLITAN DEVICE CORPORATION, .Assignee of Thomas E.-Murray, Deceased, By THOMAS E. MURRAY, Jn., n President.

THOMAS E. MURRAY, JR- 

